The Metropolitan Museum of Art launched an innovative docent training program to engage younger audiences with classical artwork. Elena Rodriguez...

Sentence Structure

• The Metropolitan Museum of Art
  • launched an innovative docent training program
    • to engage younger audiences with classical artwork.
• Elena Rodriguez and Marcus Chen
  • are just two of the talented docents
    • who [?] educational tours at the museum
      • since the program started in 2018.

Understanding the Meaning

Let's start from the beginning:

The first sentence tells us:

• The Metropolitan Museum of Art launched a docent training program
  • It was innovative
  • Its purpose was to engage younger audiences with classical artwork

Now the second sentence:

• Elena Rodriguez and Marcus Chen are just two of the talented docents
  • They're part of this program
  • There are more docents, but these are two examples

This is where we have the blank:

• 'who _____ educational tours at the museum'

Let's look at our choices:

• They differ in verb tense: conduct, will conduct, will be conducting, have conducted

To see what works here, let's read the rest of the sentence and understand what it's saying!

The sentence continues:

• 'since the program started in 2018'

Now let's understand what this time marker is telling us:

• 'Since the program started in 2018'
  • This tells us when something began – back in 2018
  • The word 'since' connects a past starting point to the present
  • It means: this action started then and has been continuing

So the complete picture is:

• Elena and Marcus have been conducting these tours starting from 2018 and continuing through to now

What do we notice about the structure here?

• The time marker 'since the program started in 2018' signals that we need a verb form that shows:
  • Action began in the past (2018)
  • Action continues to the present (they're still doing it)

This calls for the 'have/has + past participle' form

• 'who' refers back to 'Elena Rodriguez and Marcus Chen' (plural)
  • So we need: 'have conducted'

The correct answer is D. have conducted.

Grammar Concept Applied

Using the Right Verb Tense with "Since" + Past Time

When you see "since" followed by a specific point in the past, you need the present perfect tense (called present perfect in grammar terms). This tense shows that an action started in the past and continues to the present (or remains relevant to the present).

The pattern:

• Since + [specific past time] → requires have/has + past participle

Examples:

• The scientists have studied this phenomenon since 2015.
  • Action started in 2015 and continues to now
  • Time marker: "since 2015"
  • Verb form: "have studied" (present perfect)
• Maria has worked at the library since she graduated.
  • Action started at graduation and continues to now
  • Time marker: "since she graduated"
  • Verb form: "has worked" (present perfect)

In this question:

• Time marker: "since the program started in 2018"
• Subject: "who" (referring to Elena Rodriguez and Marcus Chen - plural)
• Verb form needed: "have conducted" (present perfect, plural)

Remember: The subject determines whether you use "have" (plural/I/you) or "has" (singular he/she/it). In this case, "who" refers to two people (Elena and Marcus), so we use "have conducted."